May grass grow on your cheeks and still.../ it will never happen in your lifetime/you will not live to see it/"grass will grow on your cheeks, and yet not…" (you will be dead and buried)
In a sentence: A long time will pass and still there will be no..., A long time will pass after the time of death and still there will be no...
("Rabbi Akiva used to expound: 'A star shall come forth out of Jacob'—read not 'star' but 'liar' from Jacob ... he is the King Messiah.' Rabbi Yohanan ben Torta said to him: Akiva, may grass grow on your cheeks and still the son of David will not come" — Jerusalem Ta'anit 4:5; and likewise: "May grass grow on the cheeks of the kingdom of Greece, and we will not move from here as long as there is breath in our nostrils" — Shalom Aleichem / "Our Feet Stand at the Gates of America," Rinah)
Translation
Expression (Hebrew)
יַעֲלוּ עֲשָׂבִים בִּלְחָיֶיךָ וַעֲדַיִין לֹא...
Definition (Hebrew)
בִּמְלִיצָה בְּהַשְׁאָלָה: יַעֲבֹור עוֹד זְמַן רַב וַעֲדַיִין לֹא יִהְיֶה..., יַעֲבֹור זְמַן רַב אַחֲרֵי הַתְּקוּפָה שֶׁתָּמוּת וַעֲדַיִן לֹא יִתְרַחֵשׁ...
("עֲקִיבָה רַבִּי הָיָה דּוֹרֵשׁ: דָּרַךְ כּוֹכָב מִיַּעֲקֹב- דֶּרֶךְ כֹּזֵבָא מִיַּעֲקֹב ...הוּא מַלְכָּא מְשִׁיחָא. אֲמַר לֵהּ רַבִּי יוֹחָנָן בֶּן תּוֹרְתָּא: עֲקִיבָה, יַעֲלוּ עֲשָׂבִים בִּלְחָיֶיךָ וַעֲדַיִן בֶּן דָּוִד לֹא יָבֹא"-יְרוּשַׁלְמִי תַּעֲנִית ד, ה, וְכֵן:"יַעֲלוּ עֲשָׂבִים בִּלְחָיֶיהָ שֶׁל מַלְכוּת יָוָן,וַאֲנַחְנוּ לֹא נָזוּז מִפֹּה כָּל עוֹד נְשָׁמָה בְּאַפֵּינוּ"- שָׁלוֹם עֲלֵיכֶם/ רַגְלֵינוּ עוֹמְדוֹת בְּשַׁעֲרֵי אָמֵרִיקָה, רִנָּה)